A common problem with roadway luminaires is the tendency of birds, squirrels and other small animals and insects to nest or otherwise enter inside the headcasing. The main point of entry into the headcasing is through the pre-existing annular-like opening between the headcasing and the headpole at the rear of the luminaire.
For example, squirrels may eat the insulation coating on the wires, birds may be electrocuted and die, and birds' nests may catch fire. These problems require additional maintenance to be performed and parts replacement which is costly. Nest fires may necessitate the dispatch of fire, police and service crews to deal with the resultant luminaire fire.
One approach to dealing with these problems involves the installation of a barrier device internally to the luminaire such that it forms an integral part of the luminaire, as disclosed in “Luminaire Shield Device” (U.S. Pat. No. 4,010,362) and “Fauna Guard” (U.S. Pat. No. 4,320,443). However, a drawback to this approach is that the installation of the barrier requires the disassembly of the luminaire, or in some cases, the removal of the luminaire from the headpole altogether. In practice, this labour requirement often results in maintenance workers choosing not to install the device at all, which omission cannot be ascertained by visual inspection of the luminaire from the ground.
A further drawback is that these barrier devices cannot be used to completely close off the opening due to the necessity of allowing for ±5 degrees of headcasing adjustment. This adjustment is necessary to provide for optimal lighting patterns on the roadway below and the resultant gap, notwithstanding the barrier, gives access to the luminaire.
Another approach has been to install a barrier device externally to the luminaire, as disclosed in “Luminaire Birdshield” (U.S. Pat. No. 4,434,456) and “Streetlight Light Lifetime Saver/Anti-Pollution Device” (CA Application 2,087,640), such that it may be fitted and replaced without the need to disassemble the luminaire or remove it from the headpole. Drawbacks to this device includes the physical manipulation required to install them which cannot be effectively accomplished while wearing protective gloves. As well, exposure to the elements and/or animal pecking and clawing activity, may dislodge these devices.